As portable terminals are miniaturized and made light-weight, portable terminals become more convenient to carry, and demands on the portable terminals gradually increase. Accordingly, additional functions installed in the portable terminals are diversified.
Particularly, as a function of a digital camera provided as an additional function are recognized as an indispensable component by users recently, such a function tends to be provided in most of portable terminals. Although the focus of a digital camera employed in a portable terminal basically is set on the center of a screen, the focus may be adjusted to set on another position. That is, it is possible to take a picture by diversely adjusting the focus when photographing an object using the digital camera. For example, this function is provided in products such as iPhones or iPads.
However, the digital camera employed in a portable terminal cannot obtain a desired image by focusing on another region of a previously photographed image when the photographed image is not focused exactly.
Demands of consumers on the portable terminals are diversified. Accordingly, there is a need of techniques to be developed for obtaining a desired image by refocusing on a region selected from a photographed image.
A conventional refocusing technique is disclosed in a website at http://www.cs.columbia.edu/CAVE/projects/active_refocus/, which is a technique proposed by Francesc Moreno-Noguer et al., entitled “Active Refocusing of Images and Videos.” In this technique, a projector placed in combination with a camera using a half-mirror is used to obtain a dot pattern, and depths and color segmentations corresponding to projected dots are used to compute a depth map. The depth map is used to refocus an acquired image after the dots are removed.
However, this refocusing technique has a problem in that a projector should be used in order to obtain a dot pattern needed to compute a depth map.